Do you have any experience with the ones you mentioned, and if so did either have an actual impact for you?
I’m currently using the Xanmod variant. I haven’t compared them in any objective way but I have the impression that with the Debian kernel I get slightly more stuttery games. It’s very minor though. I imagine with recent enough CPU and GPU the difference would be minimal, if any. It’s easy to switch between kernels, so it doesn’t hurt to have them all installed to try them out. In the end, whatever works for you is the best choice.
are there any details on what the additional firmware components add on?
I’m not sure. You can search dmesg for messages of missing firmware (grep for amdgpu and if there are any missing ones it should show). In any case, there are no downsides to just pulling them from upstream the way I mentioned in the post. If the driver requests them, they will be loaded and you’ll benefit from it. Firmware files that are not required by the driver will just sit on your drive taking up a little bit of space.
If there is firmware missing, some functionality of the GPU might not be available and you could have degraded performace or maybe other issues.
Anyway, if you go through the post or parts of it, let me know how it went. If there’s anything that needs correction or could be improved, I’d be glad to amend it.